HVAC cleaning procedures transmission, Jan 2003

NYC 9/11 Public Portal Document

within the exhaust ventilation system before moving on to the next grille. HEPA vacuum or wet-wipe interior surfaces of the temporary containment prior to dismantling or moving to another location. Place all waste in 6 mil polyethylene bags for disposal as asbestos-containing waste.

14. Clean the bottom of the riser using a HEPA vacuum to collect any debris that has fallen to the bottom.

15. Disengage the local capture system and relocate to another section of the riser or to another riser.

15. Ensure that the occupant space is free of any debris associated with the duct cleaning process. Use HEPA vacuums and/or wet wiping to clean the space, as needed. Place waste and debris into 6 mil polyethylene bags for disposal as asbestos-containing waste.

16. Perform all duct cleaning work in accordance with local, state and federal regulations.

17. All work will be accomplished by a DEP certified Asbestos Handlers.

18. All work will be supervised by a DEP certified Asbestos Handler Supervisor.

19. Workers will utilize inface APR’s equipped with P-100 filters, eye protection and full body coveralls during the cleaning process.

20. In most cases minimal dust accumulations were observed on components and the system has been in operation for over a year, large amounts of debris are not expected during dismantling of the system components. All specified cleaning is being performed after the installation of negative pressure ventilation equipment and system isolation devices. The existing dust/debris conditions and required engineering controls for the cleaning indicate that personal air samples are not expected to exceed 0.1 fZcc. The cleaning contractor shall collect personal air samples on workers and submit the results of sampling within 48 hours. Based on the above, the work area will not be considered as regulated area. In the event large accumulations of dust/debris are observed during the work or personal air samples exceed 0.1 f/cc work practices and engineering controls will be reevaluated and revised accordingly.

NYC-WTC_000162753